Here’s one slide from a presentation he gave at right-wing Swedish think tank.

In the text he claims that that there has been almost no rise since 1986, but in his talk (at 38:00) he told the audience to ignore the red line (which shows the ten year mean) and pointed to the graph on the bottom right of just the last eight years. Presumably he meant to write that there had been no rise since 1998. I must give him points for brazenness by doing a blatant cherry pick right in front of his audience. They seemed to buy it.

I’ll go the other way. Look at the graph on the lower right and then look at it in context in the graph on the top right with the red line showing the trend. It’s clear that warming didn’t stop in 1998 and it shows just how misleading Lindzen’s cherry pick is.

(Hat tip: Thomas Palm)

Update: William Connolley comments on David Henderson’s talk at the same conference. Henderson wants an international consortium of thinktanks to produce a critique of AR4.

Comments

If the red trend line is a 10 year mean, then it doesn’t apply if you are just looking at the years since 1998. Including the red line as it is above would mean that you are including 5 years before 1998 (if I understand the 10-year mean calculation correctly).

Now my suspicions are confirmed, that neither the host of this site nor most of its contributors including ALL commenters so far on this thread know anything about calculus. Clearly Lindzen’s point is that the rate of increase of the rate of global warming has slowed since the late 1980s, which it manifestly has. That is not cherry picking but a statement of fact from not his data but the IPCC and Hadleys’ as presented in the graphs. You are all also guilty of reverse cherry picking by ignoring the rest of his paper – even if he was wrong about the graph, and he is not, that does not mean he is always wrong, for if that were true, since he agrees with the consensus about AGM (p.3), you lot would all have to renounce it. Do try reading the paper instead of relying on Lambert’s ill advised and off target cherry picking

Tim C, he didn’t say that the rate of warming had slowed since the 80s, he said that there had been “almost no rise” since then. And the rate of warming hasn’t slowed since the 80s — it’s stayed about the same.

ok, I have a genuine question – I’m not a climate expert, by any means (I’m an engineer). This particular meme about “global warming ceasing since 1998″ has been doing the rounds, and there’s something about it that has been bugging me… I’m just looking for enlightenment from somebody who knows more about this that I do.

Leaving aside the fact that there’s statistical cherry picking going on here, is it really true that global warming can be measured by looking at temperature alone?

Here’s what I’m getting at: we’ve seen significant reductions in ice sheets in the last few years (I don’t have a reference handy, but I’m sure anybody can find one). That’s a *lot* of ice turned into water; does that not represent a significant transfer of heat into the biosphere that does not carry with it a coincident increase in temperature?

Just asking… like I said, this has been bugging me, and I’m hoping that somebody can provide an answer.

Did no one in the audience pick up on the “rapid rise from 1976 to 1986 and almost no rise since”? I could see how he might (incorrectly) get away with saying that by not pointing out that 1998 was an strong El Nino year, but 1986? Even if it was a typo, surely *someone* was able to discern where that was on the graph?

Also, as has been said elsewhere about Bob Carter, I guess he “forgot” to factor in the GISS dataset?

Tim L: do you or anyone else above know the difference between linear and logarithmic trends? clearly Lindzen was making this distinction, page 8. Picking unripe cherries out of context as you have done by misinterpreting his use of the IPCC/Hadley graphs is a waste of time.

Has anyone done a comparison that removes (or solely includes) El Nino years? I realise that these years won’t all be of the same (or similar) strength and that there are theories that warming may induce El Nino events or conditions, but it would be an interesting project at the least.

When you look at the 10-year running means, then you are obviously not looking at the most recent data. Of course that it is possible to pollute the recent data by some noise from the 1980s if someone – like the group of mostly empty brains that gather on this blog – wants to claim stupidities about the “global warming”. But the actual unfiltered data show a different story. Despite your daily prayers for the temperature to rise to make your distasteful political movement more powerful, we have not seen any measurable increase of temperature at least for 8 years. You should give up, call 911, and ask to be arrested for having tried to fool the world with this gigantic hoax.

Lubos, a ten year running mean does include the most recent data. Nor does the last 10 year mean include “noise from the 80s”. Try subtracting 10 from 2005. A five year runnning mean looks pretty much the same. Heck, pretty much any method for extracting a trend from the noise will give the same result.

“I can’t find any published support for the claim “we have not seen any measurable increase of temperature at least for 8 years” — reference/cite please? Where is your group’s data published? Link?”

He’s baking a cherry pie. If you look at 1998-2005 alone you could argue for a flat curve. Of course, if you look at 1999-2005 or 1997-2005, the illusion breaks down.

Then he puts the topping on the pie by calling us a group of mostly empty brains. Somewhere there’s a manual for rightwingnuts, “How to Communicate to Liberals” that says,
“1 Tell them what you are about to tell them
2 Tell them
3 Tell them what you told them
4 Tell them they are idiots (compared to you).”

Actually, ignoring the cherry-picking premature discovery of the top of the warming curve, Lindzen’s substantive questions, such as the logarithmic nature of the effect, might deserve some discussion, preferably by somebody whose mission is not to prove himself morally and intellectually superior, most preferably by somebody who does not take the time to explain to us that he is morally and intellectually superior.

Compare to the presentation of Dr. Henderson, who seems dedicated to mitigating the harm caused by runaway anthropogenic global climate study.

Adam, I don’t think you want to remove El Nino years. The reason they are warmer is that heat stored in the ocean is released by a temporary change in currents. Thus one way global warming could manifest itself would be stronger or more frequent El Ninos.

Looking at the red line, which is said to be a “ten year mean”, I wondered if that line is a moving average, or running mean. If so, the value at each year would be calculated by averaging the current point with the preceeding 9 points. This is different from a sliding window average, which averages data points from an equal number of years before and with the year at which it is plotted. The resulting value would be the same, if the same number of years is used. However, the moving average has a phase shift associated with it equal to half the number of years used in the average process. A sliding window average is a crude digital filter and can not produce data for the ends of a time series. There would be no way to use this form of filtering to provide data for the last 5 years. I suspect that Lindzen’s red curve is a simple trailing average, thus the last point shown for 2005 actually represents the average at about 2000 instead. If so, the red curve can not show anything about changes after 1998, IMHO.

Next, looking at the data seen in the graph in the lower LHS, one can see that it ends at 2000. The average associated with it also appears to be a moving average, thus the average curve may reflect a phase lag of 5 years (assuming the same averaging period of 10 years was used). Thus, that average curve actually ends in 1995. Small no wonder Lindzen wants to ignore the red curve when commenting on recent changes.

Hmmm. That Lindzen temperature plot? I downloaded the Northern Hemisphere data from the source he cites. First, I can get close to his “ten year mean” red line is if I use a 10 year centered box mean, then do an endpoint correction for the last five years.

But I still can’t quite reproduce it. One of the problems, perhaps, is that the data I downloaded doesn’t appear to match his. For example, his data seem to show the Northern Hemisphere temperature anomaly to be constant over the last three years–you can see it in his big graph and also in the little plot on the lower right. The data I downloaded are plotted here:http://anonymous.coward.free.fr/temp/lindzen.png

Note also that there appear to be some differences between Lindzen’s graph and mine in the late 1960’s.

“Looking at the red line, which is said to be a “ten year mean”, I wondered if that line is a moving average, or running mean. If so, the value at each year would be calculated by averaging the current point with the preceeding 9 points. This is different from a sliding window average, which averages data points from an equal number of years before and with the year at which it is plotted. The resulting value would be the same, if the same number of years is used. However, the moving average has a phase shift associated with it equal to half the number of years used in the average process. A sliding window average is a crude digital filter and can not produce data for the ends of a time series.”

As a sliding window is a digital filter and is an analog of an analog (can I say that?) low-pass filter, it exhibits ringing at particular frequencies as an analog filter would. A much more preferable design is an exponential filter, where each new filtered point is the average of the new measured datapoint and the previous filtered point.

It is easy to refute Lindzen’s comments. What makes Lindzen’s comments incredibly stupid is that he made them AFTER the climate monitoring organisations (NOAA, Hadley Centre, etc.) declared 2005 the warmest year on record, beating out the very strong El Nino year of 1998. (2005 was not an El Nino year, so its warmth was unaided by teleconnection activity, but pushed higher due to increasing GHG emissions.) This complete obliviousness (if that is a word) to the facts and to the current science of climate change throws all of what Lindzen says into question.

I do have to admit that the obviousness of “diminishing returns”, i.e. Lindzen’s logarithmic effect, had not heretofore occurred to me. But I assume this was addressed by the IPCC? Considering Lindzen was a contributor?

I was sure the pessimists would be out in force after my last comment, but Dano decided to lower the bar even further.

So rice will no longer be able to grow in a warmer, wetter, CO2-fertilized planet? This is too rich.

Anyway, I thought rice cultivation was a source of methane – another of your feared greenhouse gasses. Wouldn’t a reduction in rice cultivation mean a reduction in GHG’s? Are you sure you have your pessimist alarmist doomsday notes straight?

Yes Dano, but while the link above indicates a slight reduction in crop yeilds, you’ve eliminated them altogether. There are just no rays of sun in your dismal gloomy world, are there? “… plants that can no longer be grown…” – give me a break.

But now methane reductions are a BAD thing? Whatever. Who can keep up with these topsy-turvy alarmist arguments.

… Anyway, I thought rice cultivation was a source of methane – another of your feared greenhouse gasses. Wouldn’t a reduction in rice cultivation mean a reduction in GHG’s?

Nanny, if I can gently point out that when a reduction in rice output is noticed the first response will be to grow more rice. This will lead to more cultivation to produce the same amount of rice consequently increasing the GHG produced per kg of rice produced.

I believe that we can chalk up one for the “pessimist alarmist doomsday notes” – zero for Nanny.

I plotted it and it looks almost identical to that which you showed at your URL. I then added both a 10 year moving average and a 9 year sliding window. The two filters look about the same, as one would expect, except that the moving average is shifted 5 years in time. The data sure looks different from that on Lindzen’s slide! The filtered curves don’t “plateau” after 1998, as Lindzen seems to imply.

Time for an investigation! Call out the news hounds!! Lets have a hearing!!!

It’s quite simple, I think. The data are easily available for anyone to look at and interpret themselves, rather than relying on their favorite expert. For example here (HadCRUT3). With a simple math you see that the world has warmed 0.36C since 1980 to 2005 inclusive, which translates to a 0.138C/decade trend (or 0.069C/5 year). The absolute 5-year global temperature increases in this period have been -0.119C, 0.266C, 0.023C, -0.037C and 0.227C. No clear signs of an accelerating trend, I would say. If the world chooses to warm at the trend of the last 26 years it will be 1.311C warmer by 2100. Maybe Lindzen has a point?

“the world has warmed 0.36C since 1980 to 2005 inclusive, which translates to a 0.138C/decade trend (or 0.069C/5 year). The absolute 5-year global temperature increases in this period have been -0.119C, 0.266C, 0.023C, -0.037C and 0.227C.”

My simple math can’t get 0.119C, 0.266C, 0.023C, -0.037C and 0.227C for 5 year increases out of the data anywhere. Where did they come from?

Well, you do have to do some navigating from the link I provided, I’m afraid. Choose the non-smoothed annual series data file.
If you want to pick some cranberries, as someone seemed to suggest, you’ll find that starting in 1976 we have 0.691C warming (0.238C/decade) but, curiously enough, starting in 1977 we only obtain 0.403C warming (0.144C/decade).
Now, if you’re really fond of berries, you could even argue that 1944 to now (latest 2006 data) the world has only warmed 0.289C (0.046/decade).
I know about the hockey-stick graph, but one wonders if we’re not just looking at noise.

Dano: I’m not sure if the global temperature changes HadCRU3 tries to measure have much effect as such on plants and animals (as opposed to local changes that may or may not be related to the former). I suspect that if they were able to answer your question 1) they would be unable to differentiate between noise produced by natural variability and significant climate changes (anthropogenic or not) and 2) they would be much more concerned about other alterations of their habitat produced by man. You may feel concerned about robins reproducing 15 days earlier in the Rocky Mountains, if you want, but here in Europe we basically have no primeval vegetation left, due to human activities that took place long before the industrial revolution began.

Contrary to one of the previous posts it does now look as if 1998 was the warmest year. And that some of the ten warmest were recorded in the 1930s

It is also interesting that the global warming since 1900 has only brought us back to an insignificant level above the temperatures which were recorded in 1881 just before Krakatoa!

As a retired professional statistician, I have seen no evidence which proves that the earth is warming at the rates claimed by the enthusiasts, nor that the increase in CO2 is a lead indicator to global temperatures.

It is interesting that international funding is such that any academic who wishes to publish a paper on “THE EFFECTS OF GLOBAL WARMING and my big toe” is more likely to secure a grant than one whose fundamental research cannot be associated with climate change.